Leigh Griffiths and Erik Sviatchenko have both set off for Norway for the Champions League qualifier against Rosenborg after missing the first leg through injury.
The pair trained with their team-mates at Lennoxtown on Tuesday morning before checking in at Glasgow Airport for the flight to Trondheim.
Griffiths is expected to play some part at the Lerkendal Stadion, although he is not certain to start.
Celtic assistant manager Chris Davies said: "Leigh will be travelling with us. He has been working hard to get back.
"He is available for selection, as is Erik Sviatchenko (who is) coming with us as well.
"He (Griffiths) has obviously not been training all the time in the last few weeks, but he has had some good rehab, has worked very, very hard and he is available for us, which is a big boost."
Celtic played without a recognised striker in the goalless first leg of the third qualifying-round tie.
Moussa Dembele is out for several weeks with a hamstring injury and Griffiths was suspended for one match, but the Scotland striker would have missed the game with a calf problem anyway.
Asked if he expected Griffiths to play in Norway, Davies said: "I think so, yes, without giving away too much whether he is going to start or not. He is an important player for us and it's good for us going into the game.
"It's important (to have him available). We have a lot of players who are important in terms of scoring goals and creating chances but Griff is an important player for us, he has been since he's been here.
"The manager works closely with him, he has a good relationship with him and we are really pleased that he is available for selection."
Midfielder Tom Rogic played the 'false nine' position against the Eliteserien leaders but without success and manager Brendan Rodgers utilised winger James Forrest up front in a 5-0 friendly win over Sunderland on Saturday. Scott Sinclair has also played through the middle for Celtic.
Asked about the prospect of taking a risk with Griffiths, Davies said: "We don't want to give too much away, understandably so, but he is available with us and looking forward to the game."
With Dedryck Boyata out with a knee injury, Norwegian teenager Kristoffer Ajer made his first start for Celtic alongside Jozo Simunovic in central defence in the first leg after Sviatchenko was forced out with a groin complaint.
Davies said: "Erik is travelling so like Griff he has had a rehab process and is going to be travelling with us, which is a boost.
"We had our last training session today and Erik and Griff took part in that so they are coming with us, and that is important."